GLM works only for C++ and I plan on moving to back to C. There is a C port, but it would be good for me to figure out vertex math myself. Hence, my own library has been created.
Passing VulkanState everywhere (including windowLoop) made no sense. I know that "globals are evil", but this is the best solution for now.
Closes #30. This is a basic refactoring of the graphics module, so everything won't be in single file.